Bag making machine and method



July 8, 1941. H. w. PARRISH BAG MAKING MACHINE AND METHOD Filed May 29,1939 5 Sheets-Sheet 1 N VENTO QJ Q/a/e Q/A OI'r/S/Z a; P M I (flTTOmEZySJuly 8,1941. H. w. PARRISH BAG MAKING MACHINE AND METHOD Filed May 29,1939 5 Sheets-Sheet 2 mm RQ N V E. N rob Q/a/e Qmaxr/is/z 15, PM, cm, 61M. M1

oqTTowsy July 8, 1941. H. w. PARRISH 2,248,895

BAG MAKING MACHINE AND METHOD Filed May 29, 1939 5 Sheets-Sheet 3 mbQ/a/e Q/barrAs/z 19, FHA- M, f'

TTOQEyQ July 8, 1941. H. w. PARRISH BAG MAKING MACHINE AND METHOD FiledMay 29, 193.9 5 Sheets-Sheet 4 m J \Q v m a /w W ma, O/a/e War/Ask W iW? A fweu Make fl x N G July 8, 1941. H. w. PARRISH BAG MAKING MACHINEAND METHOD Filed May 29, 1939 5 Sheets-Sheet 5 7 IIII/fl'II/IIIII I I i"n C r H will/4 I O/a/e Q/DOI'IVS/Z Patented July 8, 1941 BAG MAKINGMACHINE AND DETHOD Hale W. Parrish, South Bend, Ind., asslgno rto KieanHolder Corporation, Detroit, Mich, a

corporation 01' Michigan Application May 29, 1939, Serial No. 276,324

20 Claims.

The invention relates to a method and machine for bag making, and moreparticularly for making bags with interiorly located lifting strips.

Bags of this character are especially handy as sanitary containers forfoods as, for example, sandwiches. For this purpose, the bag may be madeoi any suitable material such as plain paper, wax paper, Cellophane, orthe like. The lifting strip may also be made of paper and in the form ofa strip doubled upon itself. One end of the strip is attached to the bagnear its mouth and extends down into the bag with the fold of the stripat the bag bottom and the free end oi. the strip projecting from the bagmouth. When so located, the strip embraces the bag contents, and bypulling on the free end of the strip the contents may be gradually movedout of the mouth of the bag.

The general object of the present invention is to provide a novel methodand machine by which bags with interiorly located lifting strips may bemade at high speed and at very low cost.

A more specific object of the invention is to provide a method andmachine for making bags of the type described, characterized by theinitial attachment of the folded lifting strips to an advancing sheet ofbag material and subsequent folding of the sheet about the strips in bagbody form so that a lifting strip is located on the inside of each bagwhen the latter are completed.

A further object is to form the lifting strips from a roll of ribbonadvanced in synchronism with the sheet from which the bags are formed.

Another object is to provide a method and apparatus for making bags ofthe type indicated. of such character that the bags may be formed bytransversely severing a tubular piece of bag material at successivepoints without also severing lifting strips located within the tube andextending across the line of transverse severance. In this way an end ofthe strip is left projecting from the mouth of the completed bag inposition to be readily gripped by a user.

The invention also resides in various structural improvements in themachine by means of which the bag-forming, strip-forming andstripattaching operations are all accurately correlated andsynchronized.

Further objects and advantages of the invention will become apparent asthe following description proceeds, taken in connection with theaccompanying drawings, in which Figure 1 is a perspective view of afinished bag with attached lilting strip, made in accordance with themethod and by the machine herein disclosed.

Fig. 2 is a vertical sectional view along the line 22 in Fig. 1.

Fig. 3 is a genemlly schematlc perspective view showing the progress ofthe materials as they are formed into lifting strip bags like that ofFig. 1.

Fig. 4 is a detail perspective view of a forming plate utilized in thebag forming machine.

Fig. 5 is an enlarged transverse sectional view along the line 5l ofFig. 3.

Fig. 6 is a schematic side elevation 01' a bag making machine embodyingthe invention.

Fig. 'i is a diagrammatic layout or the gearing included in the drivemechanism for the machine of Fig. 6.

Fig. 8 is a side elevation, partly in vertical section, of the portionof the machine at station A in Fig. 6.

Fig. 8 is a detail stop-motion view of a portion of the mechanism ofFig. 8.

Fig. 9 is an end elevation partly in section along the line 0-9 in Fig.8' of a portion of the mechanism of Fig. 8.

Fig. 10 is a detail perspective view of one of the driving gears showingits micrometer adjustment mounting.

Fig. 11 is a side elevation of the apparatus included at stations E andF in the machine of Fig. 6.

Fig. 11 is a stop-motion view of the apparatus at station F shown inFig. 11.

Fig. 12 is a side elevation of the apparatus included in the machine ofFig. 6 between stations F and G.

Fig. 13 is a detail perspective view of part of the apparatus includedat station F, as shown in Fig. 11.

Fig. 14 is a side elevation, partly in vertical section, of theapparatus included in the machine of Fig. 6 at station B.

Figs. 15 and 16 are respectively plan and side elevations of theapparatus at station C in the machine of Fig. 6.

Fig. 17 is a fragmentary perspective view or a modified forming plateadapted to replace that 01 Fig. 4 in the machine of Fig. 6.

The invention is exemplified herein as applied to the making 01' bags lleach having a folded and interlorly located lifting strip II. Thisparticular bag is or flat form with a plain, unseamed front wall I! anda back wall formed by overlapping portions ll-|I adhesively securedtogether to form a longitudinal seam. The bottom o1 the bag is closed bydoubling the bag upon itself at I! and securing the folded end in placeby adhesive. The open upper end or mouth III of the bag may be closed bya flap l9, which constitutes an extension on the rear wall. The liftingstrip II is secured near the open end of the bag to the inner side ofthe front wall |2 by adhesive 2|I, and the free end ll of the stripprojects beyond the short front wall but short of the end I! of the rearwall, being readily accessible at the open end of the bag.

It will be understood that the present invention is applicable to themanufacture of a large variety of other forms of lifting strip bags.Consequently, even though a particular application of the invention hasbeen shown and described in some detail, there is no intention tothereby limit the invention to such application. but, on the other hand,the appended claims are intended to cover all alternative applications,methods and constructions falling within the spirit and scope of theinvention.

Briefly stated, the method herein contemplated includes the steps ofadvancing a continuous sheet of paper or other bag material in anendwise direction, attaching afolded lifting strip to the advancingsheet, folding the sheet about the strip to form a bag body, and thensevering the folded sheet to complete the bag. By first locating thestrip on the sheet and then folding it about the strip, the latter isproperly located in the interior of the completed bag. Furthermore, thismethod is particularly well adapted to be carried out by an automaticmachine operating at very high speed since successive strips may beformed from a continuously advancing ribbon and attached to the bagsheet while the latter is in motion and without interference with any ofthe bag-forming steps.

In the illustrative application of the method herein disclosed (see Fig.3), the bags iii are formed from a sheet of paper 2| unreeledcontinuously from a supply roll 22. In general, the manipulation of thesheet 2| is that commonly used in making flat paper bags and,consequently, a detailed description of the machinery for accomplishingit is believed to be unnecessary. In brief, the advancing sheet 2| firstpasses through station A where adhesive is applied along its side edge2| for subsequent completion of the longitudinal bag seam. Then, thesheet passes beheath an angular forming plate 23 (see also Fig. 4) atstation B. The side edge portions II and ii are progressively folded inover the forming plate 23 and their overlapping edges are pressedtogether so that the sheet is glued in tubular configuration. Next thetube is severed transversely at station G into successive sections III.Finally, the bottoms H of these sections are folded at station D tocomplete the bags Ill, the finished bags being carried away by theconveyor belts 2|, 25.

In addition to the usual bag forming steps outlined above, two other ornew operations are performed on the advancing sheet 2|, preferably atstation A, to condition it for receiving the lifting strips These arerespectively the cutting of the sheet to form transversely extendingslits 26 at points spaced longitudinally of the strips to correspond tothe upper ends of the rear walls of successive bags and the applicationof dabs of glue or other adhesive at points slightly in advance of eachof the slits 28. These spots of glue secure the short ends ll of thesubsequently applied lifting strips H on the sheet. The slits 26 serveto prevent tearing of the projecting tab ends H of the strips when thebag sections are severed at station C, as will hereinafter appear morefully.

The lifting strips II are also formed from a continuous length ofmaterial, in this case a ribbon of paper 21 (Fig. 3) unrolled from asupply spool 28. As this ribbon advances, it is cut into separatelengths 21' at station E, which sections are doubled or folded uponthemselves at station F to form the finished lifting strips H whichadvance with their short ends li facing the sheet 2|. The paths of theadvancing bag material 2| and strips merge at station G where the stripsare fed onto the sheet at a rate exactly matched with the latters rateof advance. The shorter portion of each successive strip II is pressedagainst a corresponding spot 20 of adhesive and located with the freeend of the longer strip leg projecting across the center slit 28. Afterthe lifting strips II have been glued to the sheet 2| in this manner atstation G, the formation of the bags l|l is continued as describedabove, the sheet 2| being folded about the strips II in the form of abag body with the strips located inside the same.

The severing of the separate bag sections ill (Fig. 3) from thetubularly folded material 2| is preferably accomplished by a tearingoperation. The lower side of the tube (as viewed in Fig. 3) can, forexample, be torn transversely by pulling it sharply up against thetrailing end edge of the forming plate 23. The difllculty is, however,that this tearing must be accomplished without also tearing of! the endll of the lifting strip which projects beyond the mouth of the bag. Itis to meet this diiiiculty that the preliminary center cuts 26 are madein the sheet. With the sheet 2| so cut the severance of the tube bottomwall can be completed by tearing this wall along transverse linesmerging with the ends of the slits 26 while not applying any substantialtearing force at the center of the sheet where the lifting strips II arelocated. For this purpose the lower end of the forming plate 23 isfashioned with a smoothly rounded center portion 29 (Fig. 4) matching inlength the center slits 26. At each side of the portion 29 cutting edgesare fashioned in the form of sharp teeth lll. With the end of theforming plate so shaped the bottom of the tubular material folded aboutit can be pulled upward, as, for example, in the usual manner of tearinga piece of paper along a straight edge, and it will be turn in twospaced lines merging with the ends of the center slits 28. Theprojecting ends H" of the lifting strips ride up over the rounded centersection 29 during this operation without being torn or harmed. It willbe apparent, however, that in order for the operation to be carried outsuccessfully, the center slits 26 must be located accurately in registrywith the end of the forming plate 23 when the tearing operation iscarried out. The machine herein disclosed is particularly adapted toaccomplish the nicety of timing required for this purpose.

An important advantage of the method described above is its adaptabilityto high speed production. The improved machine herein disclosed may beadvantageously utilized in carrying out this method. In many respects,this machine resembles those heretofore used in making flat paper bagswithout lifting strips. Accordingly, the succeeding description anddrawings are directed particularly to those parts of the machine whichare new in character and especially adapted to the manufacture of bagswith interiorly located lifting strips.

For an understanding or the general layout of the illustrative machineembodying the invention and adapted to carry out the method describedabove, reference should be had to the diagrammatic view in Fig. 6. Inthis machine, the paper sheet 2| is led from the roll 22 over freelyrevoluble guide rollers 3|, 32, then through station A, and thencebetween a pair of opposed power-driven friction guide rollers II, it atstation G which bear lightly on the paper sheet 2|. At station A, thesheet 2| passes over a power driven roller 35, which cooperates with anopposed roller 35 to form the center slits 2i and apply the spots ofadhesive 20 (see Fig. 3) in a manner hereinafter described. Also, atthis station a roller 55, running in a bath of liquid adhesive 51,applies adhesive along the side edge 2| of the sheet (see Fig. 3). Afterleaving the guide rollers 33-, the sheet 2| is drawn along the formerplate 23 by a pair of power driven draw rolls 31 and 38 which areadJusted to provide suilicient friction for pulling the sheet 2| throughthe machine. The draw rolls l1 and I5 establish the feed rate of thepaper sheet 2| and the other rolls are adjusted to rotate in synchronismtherewith. As a result of the tension exerted on the paper sheet 2| bythe rolls I1 and 38, the side edges of the sheet are folded in about theformer plate, being pressed down and pulled together by draw-in rollers58 (see also Fig. 15). At station 0, the sheet, then in tubular form, issevered into its successive sections ID by a striker bar 40 which isrevolved in a vertical plane transverse to the path of movement of thebag material. Thereafter, the sections it are fed by a pair of feedrollers "-52 into the usual mechanism at station D for folding thebottoms ll of the bags and including a pair of opposing rollers 53-.Finally, the finished bags are advanced by feed rollers 45-48 onto thetop of the conveyor belt 25.

Turning now to the mechanism for forming and applying the lifting stripsII, it will be noted that the unreeling of the paper 21 from the spool28 is accomplished by a pair of opposed power actuated feed rollers 41-Fig. 6). These feed the ribbon 21 at a speed substantially twice that ofthe sheet 2| since a piece of ribbon substantially twice the length of abag section must be provided to form the lifting strip for each bag.After leaving the feed rollers "-48, the paper ribbon 21 passes througha severing mechanism at station E embodying a pair of opposed rollers"-50, one of which carries a severing blade 95, thence through a secondset of feed rollers 5|52 to a strip folding mechanism at station I".This folding mechanism also embodies a pair of opposed rollers 53-54carrying suitable tucking or folding devices hereinafter described. Uponleaving the folding mechanism at station F, the lifting strips II arestill advancing at a speed substantially twice that of the sheet 2|.Their speeds must, however, be synchronized when their paths merge atstation G where the strips are attached to the sheet of bag material.Accordingly the rate of advance of the lifting strips ii is slowed downbetween stations F and G by passing them through successive sets ofslow-down" rollers 55-58 and 51-55, which are driven at successivelyslower speeds. The lifting strips H, as well as the sheet 2|, are passedbetween the feed rolls 33- at station G and at this point the liftingstrips are pressed against the spots ll of adhesive on the sheet of bagmaterial 2|. Then, to hold the freshly applied lifting strips inposition they are pressed against the sheet 2| by a flezdble belt 5|,made of canvas or the like, which is led over pulleys 5|, Ii, and 52.

To insure proper relative timing of the various parts of the machine,all are preferably driven through suitable gear trains from a singlesource of power such as an electric motor (not shown). In Fig. 7 thelayout of the gearing has been shown diagrammatically. In this figurethe circles indicate the pitch circles of the gears, those on the frontof the machine being shown in full lines and those on the back in dottedlines. Of course, in some instances, a gear on the front of the machinecovers a gear of the same diameter on the back of the machine. Tofacilitate an understanding of the relation of the gearing of Fig. 7 tothe associated rollers, etc. in Fig. 6, the gears of Fig. 7 which arefast on rollers of Fig. 6 have been given the same reference numeralwith the designating letter (3" added. For example, the gears on themain feed rollers 33, ll (in Fig. 6) are designated in Fig. '7 as "G andG.

Power is supplied to a drive pulley 53 (Fig. '1) which is connectedthrough bevel gears 54 with two alined drive shafts 55 and 56. Theseshafts respectively drive the parts of the machine on the right and lefthand sides of station B. Thus, the first drive shaft 65 is connectedthrough bevel gears 51 and intermediate gears 58 with the guide rollergear 33G, which is in turn connected to a gear in mesh with the secondguide roller gear G. The feed roller gears 510 and 58G are driven at asomewhat higher speed than the feed roller gears G, "G from a gear 59(fast with the gear 350) through an intermediate gear ll. Also driven bythe bevel gears 81 on the drive shaft is an intermediate gear H which,through intermediate gears 12, drives the tucking roller gears "G andSIG. Passing on down the machine, feed roller gears 5|G, 52G are driventhrough an idler it while a second idler ll meshes with one of thesevering roller gears G which in turn meshes with its complementalroller gear "G. The feed roller gears 41G, G are driven through an idler15 from an intermediate gear ll fast on the roller gear G. This lattergear also meshes with an intermediate gear ll fast on the roller gear35G which in turn drives the complemental roller gear 356.

At the left hand end of the machine (as viewed in Fig. 7) the seconddrive shaft 65 carries the rotating striker bar I. Additionally, thisshaft drives the feed roller gears MG and "G through a set of bevelgears 18. The gear G in turn meshes with an intermediate gear 19 fast ona second intermediate gear 50 which drives the draw roll gears "G and350. A sprocket 8| fast on the gear "0 drives a second sprocket 82through a chain 83, and this second sprocket is connected through gearsII with the belt pulley 60. The bag-end folding rollers 43- and feedrollers 45-55 are of conventional construction and their drive gearshave not been shown. They may, however, be driven from the shaft 55 bysuitable connecting gearing.

Bearing in mind the general layout of the machine as described above,attention may now be given to a more detailed consideration of theparticular mechanisms included at the diflerent stations in the machine.The apparatus at station A (Fig. 8) includes, as was previously noted,

a pair of cooperating rollers 85 and 88. To apply adhesive along theedge 2i of the sheet of bag material 2i (see Fig. 3) the usual glueapplying roller 85 (Fig. 8) is utilized. This roller is ioumaled in thetop of a pct 88 containing liquid adhesive 81 and is of an axial widthequal to the width of the line of adhesive to be applied to the sheet2I. The roller 85 is revolved by frictional contact of the sheet 2|against it as the latter passes over the opposed roller 85.

A second glue roller 88, fast on the roller 88. but of smaller diameterto provide clearance for a knife 88 by which the slits 28 are formed,supplies adhesive from the pot 88 to an applicator finger 88 on theupper roller 88 and this finger in turn applies the dabs 28 of adhesiveto the advancing sheet 2i at accurately spaced points. The knife 83projects from the roller 88 beyond the point of glue application makingit necessary to move the applicator finger 88 to contact the glue roller88. For this purpose, the applicator finger 88 is pivoted on the roller36 by pin 88 and a stop pin 8| on the applicator finger is urged by aspring 82 into engagement with a fixed cam 82 secured to the stationarybearing sleeve 88 (Fig. 9). The pin 8| contacts and follows the profileof the cam 82 so that the finger is projected outwardly and contacts theroller 88 thereby picking up adhesive. As the pin 9| passes the cam, itis moved by the spring 82 to the position shown in Fig. 8 in which thefinger is located for proper transfer of the adhesive to the travelingpaper web 2|. In this way the finger applies a spot of adhesive on thesheet once during each revolution of the roller 35. This latter rolleralso carries the knife or blade 85 located centrally of the sheet 2| andregisterable with a slot 84 in the opposed roller 35. The blade 83 thusforms the center slits 28 in the advancing sheet at precisely spacedpoints. The length of the center slits 28 approximates the width of thestrips II. Minimization of the slit length is desirable since in thatway maximum longitudinal tensile strength of the sheet is retained toresist rupture while being pulled through the machine.

At station E (Fig. 11) the advancing ribbon of paper 21 is severed intosuccessive sections 21 by the knife or blade 95 projecting from theperiphery of the roller 58. A cooperating recess 85' in the opposedroller 49 receives the end of the blade as it passes through the strip.The feed rollers I-52 are located sufficiently close to the rollers48-58 to grip each of the sections 21 before it is severed from thecontinuous ribbon 21 and direct it between the tucking rollers 53-54 atstation F.

At station F (Fig. 11) each successive strip section 21 is folded ordoubled upon itself to form a completed lifting strip II. For thispurpose a dull edged tucking blade or plate 85 extending longitudinallyof the roller 54 is arranged to engage each successive strip section andtuck its mid-portion into a complemental recess 81 in the cooperatinglower roller 53. The parts are so timed that each strip section ispassed between the rollers 53-54 for a little more than half its length(more than half, so that the upper leg of the folded strip will belonger than the lower leg in the finished strip) before the tuckingblade 98 contacts it and tucks it into the groove 81. The projecting endof the strip 21 which has passed on between the rollers 53-54 isreceived temporarily on a guide plate 88. The tucking blade 85 ispivoted on a. pin 88 in a V-shaped longitudinal groove I88 in the upperroller 54 and is spring-pressed toward the forward face of this grooveso that it yieldably urges the paper strip into the tucking recess 81 inthe lower roller 58.

To hold the portion of the strip 21' that has been pressed into thetucking groove or recess 81. a pivoted gripper plate I" is utilized.This plate extends longitudinally of the recess 81 and carries an armI82 and a roller I88 (Figs. 11 and 13). The pivoted arm III isspring-pressed against a peripheral stationary cam I84 (Fig. 11). andthis cam is contoured to hold the arm I82 raised. so that the gripperplate III is correspondingly lifted from the trailing face of thetucking recess 81, until the strip 21' has been thrust into the recess81 by the tucking plate 88. Thereafter, the recess in the top of the camI84 permits the arm I82 to drop down so that the gripper plate IIIIpresses the folded center portion of the paper strip 21 against thetrailing face of the tucking recess 81. Consequently. continued rotationof the roller 58 draws the strip section on about the periphery of theroller to continue the folding action along the length of the strip(Fig. 11").

To release the folded strips from the lower tucking roller 58. the camI84 is contoured to shift the gripper plate I8I to released positionafter the roller 58 reaches approximately the position shown in Fig.11a. Thereupon, the resiliency of the paper tends to cause it to snapout of the tucking recess 81 so that it is received upon a downwardlyinclined guide plate I81. To positively insure stripping of the foldedpaper from the roller 58 a plurality of fingers I88 (Fig. 13) arefashioned on the forward edge of the guide plate I81. These fingersproject into peripheral grooves I88 on the roller 58 and thus force thefolded nose of each strip of paper out of the tucking groove 81. Toprevent slippage or stopping of the strip 21 after release by thegripper plate IN a roller I85 is arranged to press the paper stripagainst the periphery of the roller 58 (Figs. 11, 11" and 13). Thisroller I85 is journaled on a pivoted arm I88 and is driven frictionaliyby the continuous end portions 58 of the roller 58 which it contacts.

Upon being freed from the lower tucking roller 58 the folded strips IIare directed to station (3 along a seriw of inclined guide plates 8(Fig. 12). The slow-down" sets of feed rollers 55-58 and 51-58 arearranged at intervals along this path so as to slow up the rate ofadvance of the folder strips II. As was previously noted, the paperribbon 21 from which the lifting strips are formed must initially be fedat a rate substantially twice that of the bag material sheet 2I butafter the strips are formed they must be slowed down so that their rateof advance matches that of the sheet of has material. In the presentmachine this is done by feeding the strips through the successive pairsof slow-down rollers which are operated at successively slower speeds.It is desirable to use a plurality of such sets of slow-down rollers soas to minimize the resultant buckling of ithe advancing strips betweeneach successive pa r.

0n reaching the guide rollers 88-84 at station G (Fig. 2) the strips IIare pressed by these rollers against the face of the advancing sheet 2i.At this point, the rates of sheet and strip advance are exactlysynchronized since both the strips and the sheet pass through this sameset of rollers. By timing the slow-up rollers (through the medium oftheir gear drives heretofore aasaaos described) the delivery of thestrips ll onto the sheet 2! is so timed that each strip will beaccurately located on the sheet with its short underside leg overlying aspot of adhesive 20 and its longer upper leg overlying a center slit Itin the sheet 2| (see. also Fig. 3). In passin through the guide rollers83-. the strips Ii are pressed against the sheet 2| so as to cause thestrips to be firmly glued in place. Incidentally, it should be notedthat the'side edge portion Il' (see Fig. 8) of the sheet 2| to whichglue has been previously applied for the bag seam is located beyond theend of the upper roller 34 so that this glue will not smear the roller.

By forming the strips II in timed relation with the advance of the sheetii, the manipulation of these strips is greatly simplified. whenutilizing this arrangement it is unnecessary to provide any intermediatestorage space for the strips prior to their delivery to the sheet andalso any problem of ting or picking these strips out of a stored batchof them is obviated.

After the strips II have been attached to the sheet II, the latter isprogressively folded into tubular or bag body form by drawing it alongand about the former plate ll (Figs. 8 and 4). In starting a sheet ofpaper Ii through the machine, its forward end portion is folded aboutthe former plate It and thrust between the draw rolls "-3! (Fig. 16).These latter rolls register with an aperture ill in the former plate andgrip the sheet at this point. Thereafter, upon starting the machine thedraw rolls pull the sheet along and it is progressively folded about theformer plate in the usual manner. The former plate II (Fig. 4) embodiesa long rectangular horizontal body portion and an upwardly inclinedportion at its leading end. Former plates of this general character arewell known in the art and. accordingly, further description of itsoperation is believed to be unnecessary. Aside from the special tearingend construction heretofore described the former plate herein showndiffers from the usual construction only in that a longitudinal slot H2(Fig. 4) is fashioned in it. This center slot forms an open way for thelifting strips ll glued on the sheet ll so that the former plate doesnot tend to dislodge them. To further aid in holding the strips II inposition the belt It (Figs. 12 and 14) is arranged to press the stripsagainst the sheet 2| while the sheet is passing along the inclinedforward portion of the former plate and any tendency of the strips toslide down this incline is thus checked.

By attaching the lifting strips II to the center portion of the sheet 2|any impediment to proper folding of the sheet about the former plate 23is avoided. In other words, the strips are attached to a part of thesheet, namely, the center portion, which is not longitudinally foldedduring the formation of the bag, but is, on the other hand, retainedsubstantially flat throughout such forming operation. As a consequencethe strips do not interfere with the longitudinal folding of the sheetinto tubular form.

The usual draw-in rollers I9 (Figs. 14 and 15) are pivotally mountedabove the horizontal porinto proper overlapping relation. Also in theusual manner a finger ill (Fig. 16) leased to push down the side edgeportion ll of the sheet so that it is held out of contact with the otheredge portion ll until the two are pulled into proper overlappingrelation for gluing them together. While passing between the draw rolls"-4! the overlapping portions "-4! of the sheet are pressed tightlytogether to complete the longitudinal bag seam.

At station C (Figs. 15 and 16) the tubularly formed sheet 2! is severedinto successive sections ill by the striker bar I. As previously noted,the end of the former plate 23 is fashioned to constitute a tearing edgeor cutter to cooperate with the striker bar for severing the bottom wallof the' tube. The upswingins st ker bar lll (Fig. 16) pulls the lowerside of the tube up across the end of the former plate 23. Consequently,the sharp teeth 30 (Fig. 4) tear this bottom tube wall along linesmerging with the center slit 26, which at this instant registers withthe end of the former plate. The projecting strip H is pulled up acrossthe rounded center part 29 of the former plate 23, however, so that itis not torn oil or damaged.

A suitable alternative former plate end is shown in Fig.17. The samereference numerals have been used for identical parts. It diil'ers fromthat of Fig. 4 only in that it is recessed at 2,9 to protect theprojecting strip end rather than having a rounded edge in its centerportion.

The striker bar I also serves to tear off the top wall of the bagmaterial tube. Cooperating with it for this purpose is a stationarycutter H6 (Figs. 15 and i6) presenting a concave series of cutting teethIll. This cutting edge or series of teeth is concave so that the topwall will be torn off along a correspondingly curved line to form theflap I! at the mouth of the completed bag (Fig. 1). Furthermore thisconcave series of teeth is offset from the end of the strips ll so thatthis upper row of teeth has no tendency to tear the projecting stripends.

After leaving station C the severed bag sections ill have their lowerends folded and glued at station D (Fig. 6) and are carried away by theconveyor belts 21-25, all in the usual manner. This apparatus followingstation C may all be of conventional form and, accordingly, furtherdescription is believed to be unnecessary.

From the foregoing description of the construction and operation of themachine it will be apparent that great nicety of timing is requiredbetween many of the parts. This problem is especially acute in view ofthe extreme speeds of material feeds encountered in turning out bags ata rate of 350 per minute as the machine above described is capable ofdoing. With such high speeds. even a small error in timing will be sogreatly multiplied in the course of a few minutes of operation as tospoil the product. The positive maintenance of a timing relation onceestablished is insured by actuating all of the parts through positivegear drives from a single or common source of power. To obtain therequired precise timing and enable the machine to be adlasted for themaking of bags of difierent lengths and widths, provision is made for:

(a) Adjustment of the fold forming mechanism so that the position of thefold in the lifting strip may be varied relative to the advancing end ofthe strip;

(b) Adjustment of the knife 93 and the glue applicator finger 88 withrespect to the movement of the lifting strip so that the folded stripswill be applied at the proper points to the advancing paper sheet: and

(c) Adjustment of the slit forming knife in relation to the striker bar40 for cutting off the successive bags.

Adjustment of the fold forming mechanism is effected by advancing orretarding the gears of the trains which extend from a common point atthe bevel gears II successively to stations F, E, and A. For thispurpose, one of the gears can be advanced one tooth or more with respectto the next meshins fiear until the one of the driven rollers selectedfor adjustment has been turned to the angular position necessary forproper timing of the operationwhich it perform. Next, the timing of theknife 03 and the applicator 89 is changed by advancing or retarding thegear 11 so that each strip ii will be delivered at exactly the rightinstant for location properly with reference to the slit 2i and the gluespot 20. Finally, the angular position of the knife 83 (Fig. 7) can bechanged by advancing or retarding the scars II and I! so that each slitit will be disposed directiv opposite the striker bar at the time thelatter acts to cut on a bag. As an incident to adjustment of the gearsII and I2, it-wiii be noted that the previously adjusted relationshipbetween the knife I! and the folding mechanism will not be disturbed.

In some instances the advance of a full tooth on one of the gears may betoo coarse an adjustment. To take care of such a contingency. variousgears in the train are adjustably secured to the shafts which carrythem. For example, at station A the gear ll (Fig. 10 and see also Fig.7) which is carried on shaft 36 of the roller It. is secured to thisshaft by a split sleeve clamp 11. Upon loosening this clamp the shaft36' can be turned relative to the gear 'Il so as to adjust its positionwith precision and through as small an angle as may be desired.Thereafter, the clamp is, of course, retightened. It will be noted thatduring this adjustment the rollers ,35 and 88 remain connected to eachother through the gears "G and 866 (Fig. 9) at the opposite end of theshaft 36" from the gear l1. Accordingly, an anular adjustment of theroller It will effect a cor p nding turning of the opposed roller 35 sothat the knife 93 always remains in proper angular position for registrywith the slot 9| in the roller 35. In the other pairs of rollerscarrying cooperating parts the adjustment of these parts may besimilarly maintained.

From the foregoing it will be seen that the relative timing of all ofthe cooperating machine parts can be adjusted with extreme precision.Having once been adjusted, the machine can be set in operation and bagsare turned out entirely automatically with the lifting strips attachedand accurately located inside them, all at a very high rate of speed.

I claim as my invention:

1. The method of forming a bag with a folded lifting strip therein,which comprises, advancing a continuous sheet of bag material in anendwise direction. attaching one end of a folded strip to thelongitudinal center portion of said sheet during the advance of thelatter and with the strip extending longitudinally of the sheet, foldingthe side edge portions of said sheet inwardly into overlapping relationwith each other and about said strip to form a bag body enclos ing saidstrip, and cutting off the folded sheet to complete the bag.

' p ises,

2. The method of forming a bag with a folded lifting strip therein,which comprises. advancing a continuous sheet of paper or the like in anendwise direction, attaching one end of a folded strip to said sheetduring the advance of the latter, folding said sheet about said strip toform a bag body, and cutting oi! the folded sheet to complete the bag.

8. The method of forming a bag witha folded lifting strip therein, whichcomprises, doubling a strip upon itself to form a lifting strip. gluingone end of the strip to a face of a sheet of bag material, and foldingthe sheet into the form of a bag body with said sheet face constitutingan inner wall of the bag.

4. The method of forming bags with a folded lifting strip in each, whichcomprises, advancing an elongated sheet of paper or the like endwise,attaching folded strips to said sheet at successive points along itslongitudinal center portion, then progressievly folding the side edgeportions of the sheet inwardly into overlapping relation with each otherand overlying said strips to bring the sheet into generally tubular bagbody configuration with the strips enclosed in the tube while retainingthe central portion oi? the sheet and to which the strips are attachedsubstantially flat, and severing the tubularized sheet at successivepoints intermediate the points of strip attachment.

5. The method of forming bags with interiorly located folded-liftingstrips which includes the steps of advancing a continuous sheet of paperand a narrower ribbon endwise along adjacent paths at continuous ratesand severing and folding strips from said ribbon at a rate synchronizedwith the rate of sheet advance, attaching the folded strips to saidsheet at spaced points thereaiong, and folding said sheet about thesuccessive strips to form bag bodies.

6. The method of forming bags with interioriy located folded liftingstrips, which includes the steps of advancing a continuous sheet ofpaper or the like endwise at a continuous rate, severing and foldingstrips from a continuously advancing ribbon at a rate synchronized withthe rate of sheet advance. attaching successive strips to the advancingsheerI at equally spaced points along the sheet, folding the sheet aboutthe strips, and cutting the folded sheet into successive bag lengthsm atpoints disposed between the successive s ps.

7. The method of forming bags with an interiorly located folded liftingstrip in each, which advancing endwise a continuous sheet of paper orthe like, slitting the sheet transversely at spaced points along itscenter line and intermediate its side edges, attaching folded strips tothe center portion of the sheet at spaced points with a free end of eachstrip overlying a corresponding slit, progressively folding the sheetabout the strips in a bag body form, and cutting on successive portionsof the sheet along zfiiznsverse lines merging with the ends of the 8.The method of forming a bag with an interiorly located folded liftingstrip having one end protruding from the bag mouth, which comprises.advancing endwise a continuous sheet of bag material, partially severingthe sheet in a transverse direction at successive points during itsadvance. then attaching folded lifting strips to the sheet at spacedpoints with a portion of each strip overlying a corresponding slit inthe sheet, folding the sheet about the strips in bag body form, andcompleting the transverse severance of the sheet at the point where itwas previously partially severed.

9. The method of forming bags each having long andshort walls and aninteriorly disposed folded lifting strip with long and short legsrespectively disposed adjacent said long and short walls, said methodcomprising advancing a sheet of bag material endwise at a uniform speed,ad-

vancing'a narrower ribbon endwise and alongside said sheet at asubstantially greater speed,

. cutting successive lengths from said ribbon, foldoff the folded sheetto complete the bag with the strip disposed therein. l

14. A bag forming machine comprising, in combination, means foradvancing in an endwise direction a continuous sheet of bag material,means for advancing a strip of material alongside said sheet and formingthe same into separated folded strips, means for attaching one end ofeach folded strip to the longitudinal center portion of the sheet whilethe latter is being advanced by said first named means and with thestrip extending longitudinally of the sheet, a former plate embodying anelongated flat body portion and an upwardly inclined leading endportion, means for drawing the sheet with the strip., attached along thebottom of said former plate and for folding the side edge portions of,the sheet progressively inward about said former 10. The method offorming bags having interiorly disposed folded lifting strips comprisingadvancing a paper sheet endwise, advancing a narrower ribbon endwise ata substantially greater speed than said sheet, cutting successivelengths from said ribbon, folding each length to form a folded strip,decreasing the speed of advance of the folded strip to bring the sameinto synchronism with saldsheet, attaching the adjacent leg of the stripto said sheet, folding the sheet longitudinally about the strip to forma bag body, and cutting the folded body into bag lengths each having afolded strip disposed there-- 11. The method of forming bags havinginteriorly disposed folded lifting strips which includes the steps ofadvancing a sheet of bag material endwise, advancing a narrower ribbonendwise at a substantially greater speed along a path substantiallymerging with the path of said sheet, cutting successive lengths fromsaid ribbon, folding each length to form a folded strip, and decreasingthe speed of advance of the folded strip to bring the same intosubstantial synchronism adjacent the points of mergence of said paths.

12. A bag forming machine comprising, in combination, means foradvancing in an endwise direction a continuous sheet of paper or thelike, means for advancing a strip of material alongside said sheet andforming the same into separated folded strips, means for attaching oneend of each folded strip to the sheet during its advance by said firstnamed means, means for folding the sheet about the strip in the form ofa bag body, and means for cutting off the folded portion of the sheet tocomplete the bag.

13. A bag forming machine comprising, in combination, means foradvancing in an endwise direction a continuous sheet of bag material,means for advancing a strip of material alongside said sheet and formingthe same into separated folded strips, means for attaching one end ofeach folded strip to the longitudinal center portion of the sheet whilethe latter is being advanced by said first named means and with thestrip extending longitudinally of the sheet, means for folding the sideedge portions of the sheet inwardly into overlapping relation with eachother and about the strip to form a bag body enclosing the strip, andmeans for cutting plate into overlapping relation while retaining thecenter portion of the sheet flat against the bottom of said formerplate, and means for cutting off the folded sheet as it leaves saidformer plate to complete the bag.

15. In a. machine of the type described, the combination of means foradvancing in an endwise direction an elongated sheet of paper or thelike, means for advancing a strip of material alongside said sheet andforming the same into separated folded strips, means for attaching thefolded strips to said sheet at successive points along its longitudinalcenter portion, means for progressively folding the side edge portionsof the sheet inwardly into overlapping relation with each other andoverlying the strips to bring the sheet into generally tubular bag bodyconfiguration with the strips enclosed in the tube, said last namedmeans being operative to retain the central portion of the sheetsubstantially flat during said folding operation, and means for severingthe tubular sheet at successive points intermediate the points of stripattachment.

16. In a machine of the type described, the combination of means foradvancing in an endwise direction a continuous sheet of paper or thelike, means for slitting the sheet transversely at spaced points alongits center line and intermediate its side edges during the advancingmovement thereof, means for advancing a strip of material alongside saidsheet and forming the same into separated folded strips, means forattaching the folded strips to the center portion of the sheet at spacedpoints with a free end of each strip overlying a corresponding slit,means for progressively folding the sheet about the strips in a bag bodyform, and means for cutting off successive portions of the sheet alongtransverse lines merging with the ends of the slits.

17. In a machine of the type described, the combination of means foradvancing in an endwise direction a continuous sheet of bag material,means for partially severing the sheet in a transverse direction atsuccessive points during its advance, means for attaching folded liftingstrips to the sheet at spaced points with a portion of each stripoverlying a corresponding slit in the sheet, means for progressivelyfolding the sheet about the strips in bag body form, and means operablein timed relation with said first named severing means for completingthe transverse severance of the sheet at the points where it waspreviously partially severed.

18. In a machine of the type described, the combination of means forfeeding a continuous sheet of paper or the like in an endwlse directionand at a substantially continuous rate, meansiorseveringandioldingsuccmsivestripsirem a continuousribbonotmaterlsLmeansiorattaehingthesuccessivcioldedstrlpstotheadvancing sheet. and mean forcorrelating the ratesoioperationofsaidflrstandseoondnamed means.

lamamachineotthetypedescrlhedthecombinationoi'meamiordirectingacontinuous sheet of paper or the likeanda contlnuousrihbon alongrespeetiveindividualpathsmergingatapolntinwhichthetwomaterlalsaremovinginthesamedirectiommeamioraeverlnganddouhlinguponitselitheadvandngrlbbontoi'ormit into successive folded strips prior to its arrival at said point,power actuated means for ieedingtheribhonintheinitlalportionotits pathat a rate substantially greater than thatotthesheetadvanceaoastocompemate for thegreaterlengthoirihhonrequiredtomatchthelengthoisheetinginviewoi'thedouhlingoitherihbomsaidpoweraetuatcdmeansalsobeing eilectlve to feed the severedand iolded portlonsoitherihbonataslowerratematching that of the sheetsubstantially at said point of path merger, and means to: attachingsuccesslve folded strips to the advancing sheet while the sheet andstrips are advancing at matched rates.

20.1n a machine oi the type described. the combination of means forfeeding in an endwise direction a sheet of bag material, means forsevering successive sections from a continuousrihbonanddoublingeachoithemuponitseli'to Vance.

HALE W. PARRISH.

